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Publication numberUS6171479 B1
Publication typeGrant
Application numberUS 09/315,110
Publication dateJan 9, 2001
Filing dateMay 18, 1999
Priority dateJul 14, 1998
Fee statusLapsed
Also published asUS6017845
Publication number09315110, 315110, US 6171479 B1, US 6171479B1, US-B1-6171479, US6171479 B1, US6171479B1
InventorsCesar Ovalles, Alfredo Morales, Luis A. Rivas, Nora Urbano
Original AssigneeIntevep, S.A.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Microwave heated catalyst and process
US 6171479 B1
Abstract
A process comprises providing a catalyst comprising a support, a microwave absorption material, and a catalytically active phase; heating the catalyst with a source of microwave energy which is absorbed by said microwave absorption material to increase the temperature of the catalyst to a desired temperature; and contacting said heated catalyst with a hydrocarbon feedstock for upgrading same.
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Claims(12)
What is claimed is:
1. A process for hydrotereating a hydrocarbon feedstock comprising:
providing a catalyst comprising a support, a microwave absorption material, and a catalytically active phase;
heating the catalyst with a source of microwave energy so as to increase the temperature of the catalyst to a conversion temperature; and
contacting said hydrocarbon feedstock with the heated catalyst.
2. A process according to claim 1 including providing microwave energy in the range of about 1 MHz to 10,000 MHz.
3. A process according to claim 2 including providing microwave energy in the range of about 800 MHz to 3,000 MHz.
4. A process according to claim 1 including heating the catalyst to a temperature of less than or equal to (≦) 350° C.
5. A process according to claim 1 wherein the microwave absorption material is incorporated in the support.
6. A process according to claim 5 wherein the microwave absorption material is characterized by a dielectric loss factor of greater than or equal to (≧) 1×10−2.
7. A process according to claim 6 wherein the microwave absorption material is selected from the group consisting of SiC, MoS2, NiS, CoS, FeS, iron oxide, nickel oxide, chromium oxide and mixtures thereof.
8. A process according to claim 7 wherein the inorganic oxide material is selected from the group consisting of alumina, silica, zirconium oxide, magnesium oxide, titanium oxide and mixtures thereof.
9. A process according to claim 8 wherein the catalytically active phase is selected from the group consisting of transition metal sulfides and mixtures thereof.
10. A process according to claim 5 wherein the ratio of inorganic oxide material to microwave absorption material in the support is between about 80:20 to 20:80.
11. A process according to claim 10 including the step of forming catalyst particles having a grain size of less than or equal to (≦) 1.7 mm.
12. A process according to claim 1 including the steps of providing:
a support comprising an inorganic oxide material;
a microwave absorption material selected from the group consisting of SiC, iron oxide and mixtures thereof; and
a catalytically active phase selected from the group consisting of transition metal sulfides and mixtures thereof.
Description

This is a Division of application Ser. No. 09/115,052, filed Jul. 14, 1998 now U.S. Pat. No. 6,017,845.

BACKGROUND OF THE INVENTION

The present invention relates to an improved catalyst support and catalyst and, more particularly, a catalyst support and catalyst for use in a process for upgrading hydrocarbon feedstocks.

The prior art is replete with catalysts for use in processes for upgrading hydrocarbons to higher value products. Most of the aforesaid processes are carried out at elevated temperatures under controlled conditions. The processes tend to be expensive as a result of the high energy input required to carry out the processes at elevated temperatures and pressures. Catalysts are employed in the processes for various reasons, including, but not limited to, reducing the temperatures and pressures at which the hydrocarbon conversion reaction takes place.

Naturally, it would be highly desirable to provide improved catalyst supports and catalysts for use in hydrocarbon conversion processes which would allow for the hydrocarbon conversion to take place at significantly lower temperatures and pressures than heretofore attainable.

Accordingly, it is the principle object of the present invention to provide an improved catalyst support and catalyst for use in hydrocarbon conversion processes for the conversion of hydrocarbons to products of higher value.

It is a further object of the present invention to provide a process, catalyst and catalyst support which allows for the hydrocarbon conversion processes to be carried out under more favorable conditions of temperature and pressure.

It is another object of the present invention to provide a catalyst and catalyst support which is useful in combination with microwave energy to convert hydrocarbon feeds to higher quality products.

Further objects and advantages of the present invention will appear hereinbelow.

SUMMARY OF THE INVENTION

In accordance with the present invention, the foregoing objects and advantages are readily obtained.

The process of the present invention comprises providing a catalyst comprising a support, a microwave absorption material, and a catalytically active phase; heating the catalyst with a source of microwave energy which is absorbed by said microwave absorption material to increase the temperature of the catalyst to a desired temperature; and contacting said heated catalyst with a hydrocarbon feedstock for upgrading same.

In further accordance with the present invention, the catalyst includes a microwave absorption material characterized by a dielectric loss factor of greater than or equal to 1×10−2, preferably, 1×10−1. The dielectric loss factor is defined as tan δ and is equal to e″/e′ in which e″ is the dielectric loss constant and is associated with the ability of the material to transform microwave into heat and, e′ is the dielectric constant associated with ability of the material to be polarized in an electric field. More information about this subject can be found in MINDOS, D. M.; BAGHURST, D. R., Chem. Soc. Rev., 20, 1 (1991) and references cited herein. In accordance with the present invention, the microwave absorption material may be incorporated into the catalyst support, formed as a single compound with the catalytically active phase, and/or included as a separate element in the final catalyst product. In accordance with the preferred embodiment of the present invention, the catalytically active phase is selected from the group consisting of transition metal sulfides and is deposited on a support material which is, preferably, an inorganic oxide material.

DETAILED DESCRIPTION

The present invention relates to an improved catalyst and a process for upgrading hydrocarbon feedstocks employing the catalyst. The catalyst of the present invention comprises a support, a microwave absorption material, and a catalytically active phase. In accordance with the present invention, the catalyst support is formed of an inorganic oxide material selected from the group consisting of alumina, silica, zirconium oxide, magnesium oxide, titanium oxide and mixtures thereof. The microwave absorption material in the final catalyst product is selected from the group consisting of compounds of Si, Fe, Ni, Cr, S and mixtures thereof. Particularly suitable microwave absorption materials include SiC, MoS2, NiS, CoS, FeS, iron oxide, nickel oxide, chromium oxide and mixtures thereof.

In order to carry out a hydrocarbon conversion process, the catalyst of the present invention includes a catalytically active phase. In accordance with the present invention, it is preferred that the catalytically active phase is selected from the group consisting of transition metal sulfides and mixtures thereof. In accordance with the preferred embodiment of the present invention, the catalytically active phase and microwave absorption material may be formed in a single compound. It is a critical feature of the present invention that the microwave absorption material is characterized by a dielectric loss factor of greater than or equal to 1×10−2, preferably, 1×10−1. Accordingly, if the microwave absorption material and catalytically active phase are formed in a single compound, the compound must have a dielectric loss factor greater than or equal to 1×10−2, preferably, 1×10−1. Suitable compounds for use in the catalyst of the present invention consist of MoS2, NiS, CoS, FeS, and mixtures thereof.

In accordance with the present invention, the composition of the catalyst is as follows: the support is present in the amount of between about 10 to 95 wt %, the microwave absorption material is present in an amount of between about 1 to 80 wt %, and the catalytically active phase is present in an amount of between about 1 to 50 wt %, all with respect to the total weight of the final catalyst. Preferably, the support is present in an amount between about 70 to 90 wt %, the microwave absorption material is present in an amount of between about 1 to 60 wt %, and the catalytically active phase is present in an amount of between about 1 to 20 wt %. It is preferred that the catalytically active phase be deposited directly on the support.

It is preferred that the catalyst be formed of grains having a grain size of less than or equal to 1.7 mm and preferably between 1.0 to 1.7 mm.

As noted above, the catalyst support may include the inorganic oxide material and the microwave absorption material wherein the ratio of the inorganic oxide material to the microwave absorption material in the support is between about 80:20 to 20:80. The catalytically active phase may then be deposited on the support structure so as to form the final catalyst product. Alternatively, the catalyst support may consist of only the inorganic oxide material and the microwave absorption material and catalytically active material may be deposited on the support as is known in the prior art. Furthermore, as noted above, the catalytically active phase and microwave absorption material may be in the form of a single compound which is deposited on the catalyst support.

The catalyst of the present invention allows for a process for upgrading hydrocarbon feedstocks which is efficient and economical. By providing a catalyst which includes therein a microwave absorption material, microwave energy can be provided to preferentially heat the catalyst to a temperature which allows for the hydrocarbon conversion process to take place without requiring the energy input necessary to heat an entire reactor to the requisite temperature as done in conventional processes. The process of the present invention comprises the following steps: providing a catalyst comprising a support, a microwave absorption material, and a catalytically active phase; heating the catalyst with the source of microwave energy so as to increase the temperature of the catalyst to a desired reaction temperature; and contacting a hydrocarbon feedstock with the heated catalyst for upgrading the hydrocarbon feedstock. In accordance with the process of the present invention, the catalyst is heated to a temperature of less than or equal to 350° C. This is accomplished by providing microwave energy in the range of between about 1 Mhz to 10,000 Mhz. Preferably between about 800 Mhz to 3,000 Mhz. The process is carried out at pressures of less than or equal to 200 psi. By employing the catalyst in accordance with the present invention, effective conversion of the hydrocarbon feedstock takes place under lower pressure and temperature conditions used in conventional processes.

The effectiveness of the process of the present invention employing the catalyst of the present invention will be demonstrated by the following examples.

EXAMPLE 1

The catalyst samples M-1 through M-5 prepared by a coimpregnation method, with a metal contents (catalytically active phase) of 8.8% Mo, 4.4% P and 2.2% Ni, using a Al2O3/SiC support (balance by wt. %) with different ratios Al2O3/SiC and a grain size of 1-1.7 mm, were tested for the hydrodesulfurization (HDS) and hydroconversion of vacuum gas oil (VGO) which contained 2.27% of sulfur (w/w) and 48% of the >500° C. distillates. In a typical experiment, 35 g of feed were mixed with 7 g of each catalyst to obtain a VGO/Catalyst ratio of 5. The samples were placed in a batch glass reactor and heated with a microwave oven (630 Watts and 2450 MHz) without stirring at 140 psi of pressure of hydrogen introduced at a flow rate of 47 cc/min. The time of radiation exposure was 110 min. for each catalyst and the total reaction time (includes the cycles on and off of the radiation) was 180 min. The sulfur content and conversion of the >500° C. distillates were determined after the test. The results are shown in Table 1.

TABLE 1
Effect of the Al2O3/SiC ratio of the inorganic oxide
material to microwave absorption material on the HDS and
>500° C. distillates conversion for experiences done with
the VGO (2.27% of sulfur (w/w) and 48% of the >500° C.).
Catalyst T (° C.) % Conversion
(Al2O3/SiC) (±3° C.) % HDS Fraction >500° C.
M-1 354 25 50
(1/1)
M-2 357 52 42
(2/1)
M-3 355 64 39
(3/1)
M-4 354 45 28
(4/1)
M-5 354 38 24
(5/1)

This example demonstrates the existence of an optimum in the Al2O3/SiC ratio of the support for the catalyst of the present invention to obtain a maximum sulfur removal (%HDS=64%).

EXAMPLE 2

Different compounds based on Mo and Ni as oxide or sulfide and supported over alumina or alumina+SiC or alumina+Fe2O3, which have different dielectric loss factor (tan δ), were tested for the hydrodesulfurization (HDS) and hydroconversion of vacuum gas oil (VGO) which contained 2.27% of sulfur (w/w) and 48% of the >500° C. distillates at the same operation conditions described in Example 1. The results are shown in Table 2.

TABLE 2
tan δ1 % Conv.
Ex- 2467 MHZ Fraction
perience Material T(° C.) 350° C. % HDS2 >500° C.
1 MoS2 + NiS/ 355 ± 3 no determ. 42 15
Al2O3
2 MoO2 + NiO/ 200 ± 3 0.031 4 0
Al2O3
3 MoS2 + NiS/ 355 ± 3 >0.20 64 39
Al2O3-SiC
4 Al2O3-SiC 352 ± 3 0.20 3 0
5 MoS2 + NiS/ 350 ± 4 no determ. 21 15
Fe2O3-Al2O3

These examples demonstrate that when the Mo and Ni are on the oxide form (Experience 2) the tan δ is lower than when they are in the sulfide form (Experience 1) and the temperature reached in the first case is lower and also is the HDS obtained. Also it is demonstrated that when the active phase is not present (MoS2+NiS) (Experiences 2 and 4) the catalyst is not active for the HDS reaction and >500° C. fraction conversion. These examples also demonstrate that the MoS2+NiS/Fe2O3—Al2O3 catalyst is also active for the HDS of a vacuum gas oil with microwave heating as well as for the >500° C. fraction conversion.

EXAMPLE 3

The effectiveness of the catalyst of the present invention with a Al2O3/SiC ratio of 3/1 in the microwave heated process was compared with a conventionally thermal process for the hydrodesulfurization (HDS) and hydroconversion of three different feeds: a vacuum gas oil (VGO) which contained 0.67% of sulfur (w/w) and 10% of the >500° C. distillates (named PLC), another vacuum gas oil (VGO) which contained 2.27% of sulfur (w/w) and 48% of the >500° C. distillates (named AMUAY) and a residual with 3.90% of sulfur (w/w) and 71% of the >500° C. distillates (named Morichal). All the experiences were carried out under the same conditions as Example 1. The results are shown in Table 3.

TABLE 3
Source of T(° C.) % Conversion
Feed heating (±3) % HDS2 350-500° C.
GOV PLC MW 350 80 0
GOV PLC Thermally 350 73 0
GOV AMUAY MW 350 64 39
GOV AMUAY Thermally 350 51 0
Residue MW 350 30 44
Morichal
Residue Thermally 350 24 27
Morichal

This example demonstrates that the process of the present invention presents better results for the hydrodesulfurization and for the conversion of the >500° C. fraction than those found for the conventional thermal process.

This invention may be embodied in other forms or carried out in other ways without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered as in all respects illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and all changes which come within the meaning and range of equivalency are intended to be embraced therein.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US5472581 *Nov 8, 1994Dec 5, 1995Queen's UniversityMicrowave production of C2 hydrocarbons, using a carbon catalyst
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US6797126Apr 3, 2002Sep 28, 2004Reactive Energy LlcCatalytic hydrogenation; applying microwaves
US7157401Oct 17, 2002Jan 2, 2007Carnegie Mellon UniversityCatalyst for the treatment of organic compounds
US7387712Oct 17, 2002Jun 17, 2008Carnegie Mellon UniversityCatalytic process for the treatment of organic compounds
US7625832Dec 5, 2006Dec 1, 2009Carnegie Mellon UniversityCatalyst for the treatment of organic compounds
US8039652Apr 14, 2010Oct 18, 2011Carnegie Mellon UniversityMethods for producing biodiesel
US8403043Nov 14, 2008Mar 26, 2013Saudi Arabian Oil CompanyMicrowave-promoted desulfurization of crude oil
US8598067Nov 9, 2010Dec 3, 2013Exxonmobil Research And Engineering CompanyInterstitial metal hydride catalyst systems and associated processes
US8618010Nov 17, 2010Dec 31, 2013Exxonmobil Research And Engineering CompanyInterstitial metal hydride catalyst activity regeneration process
US8637424Nov 9, 2010Jan 28, 2014Exxonmobil Research And Engineering CompanyIntegrated interstitial metal hydride catalyst support systems and associated processes
DE102005001726A1 *Jan 13, 2005Jul 27, 2006Robert Seuffer Gmbh & Co. KgPurifying air, especially in a room, by passage through coarse and fine filters, using continuous or periodic heating with microwaves to regenerate the fine filter
DE102005001726B4 *Jan 13, 2005Nov 6, 2008Robert Seuffer Gmbh & Co. KgVerfahren und Vorrichtung zur Reinigung von Luft, insbesondere Raumluft
WO2002086022A1 *Apr 4, 2002Oct 31, 2002Travis HoneycuttProcess for the desulphurization and upgrading fuel oils
Classifications
U.S. Classification208/216.00R, 208/143, 208/108
International ClassificationB01J27/051, C10G32/00, B01J27/224, C10G45/02, B01J23/88, B01J19/12
Cooperative ClassificationB01J2219/1281, C10G32/00, C10G45/02, B01J27/0515, B01J27/224, B01J23/88, B01J2219/0879, B01J19/126
European ClassificationC10G45/02, B01J27/051A, B01J19/12D6, B01J27/224, B01J23/88, C10G32/00
Legal Events
DateCodeEventDescription
Mar 8, 2005FPExpired due to failure to pay maintenance fee
Effective date: 20050109
Jan 10, 2005LAPSLapse for failure to pay maintenance fees
Jul 28, 2004REMIMaintenance fee reminder mailed